TagPollution Control Hearings Board(1532)

Exhibit 2141 was not present at time of scanning. Administrative Record number AR 034564.02. No substantive content available; placeholder page only.

Washington Administrative Code regulation governing mixing zones for surface water discharges in Washington State. The regulation establishes size limits, conditions, and requirements for mixing zones in rivers, streams, estuaries, lakes, and oceanic waters, including rules for acute criteria exceedance zones, overlapping mixing zones, storm water discharges, and combined sewer overflows. Dischargers must fully apply AKART

This document presents a preliminary dilution analysis for proposed stormwater outfalls around Sea-Tac Airport (STIA), noting that standard 7Q10 and 30Q5 flow conditions are inappropriate critical conditions because stormwater discharge is extremely unlikely during those low-flow periods. A site-specific approach is proposed using higher-probability discharge combinations derived from 47 years of HSPF simulation data, estimating

Handwritten notes outlining eight key discussion points related to mixing zones (MZ) and regulatory issues. Topics include stream dynamics, NPDES application, weight of evidence for defensibility, the meaning of ‘reasonable,’ contact with Norm Glen and Kevin, whether mixing zones are appropriate, regulatory flexibility for site accommodation, and the challenge of selling mixing zones especially with

This document discusses compliance points for stormwater discharges to surface waters, identifying four key problems including determining discharge locations, establishing approved design storms for mixing zones, criteria for expanded mixing zones, and critical receiving water conditions. It provides example situations for identifying compliance points and discusses Washington State water quality standards requirements for mixing zones.

This document outlines the methodology for a mixing zone analysis for the 3rd Runway North discharge to Miller Creek, focusing on Basin SDW-1. It details design storm methods using Waterworks, hyetographs, design precipitations, and design flows for both acute and chronic effluent criteria. Basin parameters including pervious and impervious areas, detention pond routing, and a

Exhibit 2084 from Administrative Record AR 033383.01 was not present at the time of scanning. This is a placeholder document indicating a missing exhibit. No substantive content is available.

This document has been marked as withdrawn and contains no substantive content. The page displays only the word ‘WITHDRAWN’ along with the administrative reference number AR 024333.

Letter and memorandum from EPA Assistant Administrator Robert Perciasepe transmitting the final Interim Permitting Approach for Water Quality-Based Effluent Limitations in Storm Water Permits to State Water Program Directors and EPA Water Management Division Directors. The policy addresses NPDES storm water permit effluent limitations, adopting best management practices (BMPs) in lieu of numeric water quality-based

This document is a fact sheet accompanying an NPDES (National Pollutant Discharge Elimination System) permit issued to the Port of Seattle for Seattle-Tacoma International Airport, governing how the airport manages and discharges treated industrial wastewater and stormwater. It covers discharge locations into Puget Sound, Des Moines Creek, Miller Creek, and the City of SeaTac storm sewer system, and establishes effluent limitations and monitoring requirements. The permit addresses water quality standards, pollution prevention plans, and compliance schedules to protect surrounding waterways from airport-related contaminants.